/* 

 * A JavaScript implementation of the RSA Data Security, Inc. MD5 Message 

 * Digest Algorithm, as defined in RFC 1321. 

 * Version 1.1 Copyright (C) Paul Johnston 1999 - 2002. 

 * Code also contributed by Greg Holt 

 * See http://pajhome.org.uk/site/legal.html for details. 

 */ 

   

/* 

 * Add integers, wrapping at 2^32. This uses 16-bit operations internally 

 * to work around bugs in some JS interpreters. 

 */ 

function safe_add(x, y)  

{  

 var lsw = (x & 0xFFFF) + (y & 0xFFFF)  

 var msw = (x >> 16) + (y >> 16) + (lsw >> 16)  

 return (msw << 16) | (lsw & 0xFFFF)  

}  

   

/* 

 * Bitwise rotate a 32-bit number to the left. 

 */ 

function rol(num, cnt)  

{  

 return (num << cnt) | (num >>> (32 - cnt))  

}  

   

/* 

 * These functions implement the four basic operations the algorithm uses. 

 */ 

function cmn(q, a, b, x, s, t)  

{  

 return safe_add(rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b)  

}  

function ff(a, b, c, d, x, s, t)  

{  

 return cmn((b & c) | ((~b) & d), a, b, x, s, t)  

}  

function gg(a, b, c, d, x, s, t)  

{  

 return cmn((b & d) | (c & (~d)), a, b, x, s, t)  

}  

function hh(a, b, c, d, x, s, t)  

{  

 return cmn(b ^ c ^ d, a, b, x, s, t)  

}  

function ii(a, b, c, d, x, s, t)  

{  

 return cmn(c ^ (b | (~d)), a, b, x, s, t)  

}  

   

/* 

 * Calculate the MD5 of an array of little-endian words, producing an array 

 * of little-endian words. 

 */ 

function coreMD5(x)  

{  

 var a = 1732584193  

 var b = -271733879  

 var c = -1732584194  

 var d = 271733878  

   

 for(var i = 0; i < x.length; i += 16)  

 {  

  var olda = a  

  var oldb = b  

  var oldc = c  

  var oldd = d  

   

  a = ff(a, b, c, d, x[i+ 0], 7 , -680876936)  

  d = ff(d, a, b, c, x[i+ 1], 12, -389564586)  

  c = ff(c, d, a, b, x[i+ 2], 17, 606105819)  

  b = ff(b, c, d, a, x[i+ 3], 22, -1044525330)  

  a = ff(a, b, c, d, x[i+ 4], 7 , -176418897)  

  d = ff(d, a, b, c, x[i+ 5], 12, 1200080426)  

  c = ff(c, d, a, b, x[i+ 6], 17, -1473231341)  

  b = ff(b, c, d, a, x[i+ 7], 22, -45705983)  

  a = ff(a, b, c, d, x[i+ 8], 7 , 1770035416)  

  d = ff(d, a, b, c, x[i+ 9], 12, -1958414417)  

  c = ff(c, d, a, b, x[i+10], 17, -42063)  

  b = ff(b, c, d, a, x[i+11], 22, -1990404162)  

  a = ff(a, b, c, d, x[i+12], 7 , 1804603682)  

  d = ff(d, a, b, c, x[i+13], 12, -40341101)  

  c = ff(c, d, a, b, x[i+14], 17, -1502002290)  

  b = ff(b, c, d, a, x[i+15], 22, 1236535329)  

   

  a = gg(a, b, c, d, x[i+ 1], 5 , -165796510)  

  d = gg(d, a, b, c, x[i+ 6], 9 , -1069501632)  

  c = gg(c, d, a, b, x[i+11], 14, 643717713)  

  b = gg(b, c, d, a, x[i+ 0], 20, -373897302)  

  a = gg(a, b, c, d, x[i+ 5], 5 , -701558691)  

  d = gg(d, a, b, c, x[i+10], 9 , 38016083)  

  c = gg(c, d, a, b, x[i+15], 14, -660478335)  

  b = gg(b, c, d, a, x[i+ 4], 20, -405537848)  

  a = gg(a, b, c, d, x[i+ 9], 5 , 568446438)  

  d = gg(d, a, b, c, x[i+14], 9 , -1019803690)  

  c = gg(c, d, a, b, x[i+ 3], 14, -187363961)  

  b = gg(b, c, d, a, x[i+ 8], 20, 1163531501)  

  a = gg(a, b, c, d, x[i+13], 5 , -1444681467)  

  d = gg(d, a, b, c, x[i+ 2], 9 , -51403784)  

  c = gg(c, d, a, b, x[i+ 7], 14, 1735328473)  

  b = gg(b, c, d, a, x[i+12], 20, -1926607734)  

   

  a = hh(a, b, c, d, x[i+ 5], 4 , -378558)  

  d = hh(d, a, b, c, x[i+ 8], 11, -2022574463)  

  c = hh(c, d, a, b, x[i+11], 16, 1839030562)  

  b = hh(b, c, d, a, x[i+14], 23, -35309556)  

  a = hh(a, b, c, d, x[i+ 1], 4 , -1530992060)  

  d = hh(d, a, b, c, x[i+ 4], 11, 1272893353)  

  c = hh(c, d, a, b, x[i+ 7], 16, -155497632)  

  b = hh(b, c, d, a, x[i+10], 23, -1094730640)  

  a = hh(a, b, c, d, x[i+13], 4 , 681279174)  

  d = hh(d, a, b, c, x[i+ 0], 11, -358537222)  

  c = hh(c, d, a, b, x[i+ 3], 16, -722521979)  

  b = hh(b, c, d, a, x[i+ 6], 23, 76029189)  

  a = hh(a, b, c, d, x[i+ 9], 4 , -640364487)  

  d = hh(d, a, b, c, x[i+12], 11, -421815835)  

  c = hh(c, d, a, b, x[i+15], 16, 530742520)  

  b = hh(b, c, d, a, x[i+ 2], 23, -995338651)  

   

  a = ii(a, b, c, d, x[i+ 0], 6 , -198630844)  

  d = ii(d, a, b, c, x[i+ 7], 10, 1126891415)  

  c = ii(c, d, a, b, x[i+14], 15, -1416354905)  

  b = ii(b, c, d, a, x[i+ 5], 21, -57434055)  

  a = ii(a, b, c, d, x[i+12], 6 , 1700485571)  

  d = ii(d, a, b, c, x[i+ 3], 10, -1894986606)  

  c = ii(c, d, a, b, x[i+10], 15, -1051523)  

  b = ii(b, c, d, a, x[i+ 1], 21, -2054922799)  

  a = ii(a, b, c, d, x[i+ 8], 6 , 1873313359)  

  d = ii(d, a, b, c, x[i+15], 10, -30611744)  

  c = ii(c, d, a, b, x[i+ 6], 15, -1560198380)  

  b = ii(b, c, d, a, x[i+13], 21, 1309151649)  

  a = ii(a, b, c, d, x[i+ 4], 6 , -145523070)  

  d = ii(d, a, b, c, x[i+11], 10, -1120210379)  

  c = ii(c, d, a, b, x[i+ 2], 15, 718787259)  

  b = ii(b, c, d, a, x[i+ 9], 21, -343485551)  

   

  a = safe_add(a, olda)  

  b = safe_add(b, oldb)  

  c = safe_add(c, oldc)  

  d = safe_add(d, oldd)  

 }  

 return [a, b, c, d]  

}  

   

/* 

 * Convert an array of little-endian words to a hex string. 

 */ 

function binl2hex(binarray)  

{  

 var hex_tab = "0123456789abcdef" 

 var str = "" 

 for(var i = 0; i < binarray.length * 4; i++)  

 {  

  str += hex_tab.charAt((binarray[i>>2] >> ((i%4)*8+4)) & 0xF) +  

      hex_tab.charAt((binarray[i>>2] >> ((i%4)*8)) & 0xF)  

 }  

 return str  

}  

   

/* 

 * Convert an array of little-endian words to a base64 encoded string. 

 */ 

function binl2b64(binarray)  

{  

 var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" 

 var str = "" 

 for(var i = 0; i < binarray.length * 32; i += 6)  

 {  

  str += tab.charAt(((binarray[i>>5] << (i%32)) & 0x3F) |  

           ((binarray[i>>5+1] >> (32-i%32)) & 0x3F))  

 }  

 return str  

}  

   

/* 

 * Convert an 8-bit character string to a sequence of 16-word blocks, stored 

 * as an array, and append appropriate padding for MD4/5 calculation. 

 * If any of the characters are >255, the high byte is silently ignored. 

 */ 

function str2binl(str)  

{  

 var nblk = ((str.length + 8) >> 6) + 1 // number of 16-word blocks  

 var blks = new Array(nblk * 16)  

 for(var i = 0; i < nblk * 16; i++) blks[i] = 0  

 for(var i = 0; i < str.length; i++)  

  blks[i>>2] |= (str.charCodeAt(i) & 0xFF) << ((i%4) * 8)  

 blks[i>>2] |= 0x80 << ((i%4) * 8)  

 blks[nblk*16-2] = str.length * 8  

 return blks  

}  

   

/* 

 * Convert a wide-character string to a sequence of 16-word blocks, stored as 

 * an array, and append appropriate padding for MD4/5 calculation. 

 */ 

function strw2binl(str)  

{  

 var nblk = ((str.length + 4) >> 5) + 1 // number of 16-word blocks  

 var blks = new Array(nblk * 16)  

 for(var i = 0; i < nblk * 16; i++) blks[i] = 0  

 for(var i = 0; i < str.length; i++)  

  blks[i>>1] |= str.charCodeAt(i) << ((i%2) * 16)  

 blks[i>>1] |= 0x80 << ((i%2) * 16)  

 blks[nblk*16-2] = str.length * 16  

 return blks  

}  

   

/* 

 * External interface 

 */ 

function hexMD5 (str) { return binl2hex(coreMD5( str2binl(str))) }  

function hexMD5w(str) { return binl2hex(coreMD5(strw2binl(str))) }  

function b64MD5 (str) { return binl2b64(coreMD5( str2binl(str))) }  

function b64MD5w(str) { return binl2b64(coreMD5(strw2binl(str))) }  

/* Backward compatibility */ 

function calcMD5(str) { return binl2hex(coreMD5( str2binl(str))) }  

module.exports = {
	hexMD5: hexMD5,
	hexMD5w: hexMD5w
}